The present invention relates to transition metal organometallic compounds with an indenyl ligand attached in position 2 and fused in position 5,6, and also to a process for the production thereof and to the use thereof as catalysts for the (co)polymerization of olefinic and/or diolefinic monomers.
In accordance with IUPAC nomenclature, the positions of the ring atoms of indene are designated as follows in the present application: 
Stereo-rigid chiral metallocenes having bridged indenyl ligands are known as catalysts for the production of polyolefins. It has been found in this connection that the nature and position of the substituents on the indenyl anion and the nature and position of the bridging have an influence both upon catalyst activity and upon polymer properties. Many indenyl metallocenes are bridged in position 1 (1-indenyl metallocenes).
Bis(1-indenyl) metallocenes substituted in position 2 and/or 4 with indenyl residues bridged in position 1 are of particular significance in the production of highly isotactic polypropylene having elevated crystallinity and an elevated melting point. (EP-A1-485 821, EP-A1-485 823, EP-A2-519 237). Bis(1-indenyl) metallocenes benzo-fused in position 4,5 are also of significance (c.f. Organometallics 1994, 13, 964-970).
It is also known to use organometallic compounds with only one indenyl anion as catalysts (constrained geometry complexes with 1-indenyl ligands, c.f. U.S. Pat. No. 5,026,798, WO-97/15583-A1).
WO-94/11406-A1 discloses transition metal organometallic compounds which comprise one indenyl and one cyclopentadienyl ligand, wherein the indenyl ligand is substituted in position 2; this substituent may also act as a bridge to the second ligand. The practical Examples show multistage production processes with highly unsatisfactory yields which, in the case of bridged compounds, give rise to 1-cyclopentadienyl-2-(2-indenyl)ethanezirconium chloride, to bis(2-indenyl)methanezirconium chloride or to dimethyl-bis(2-indenyl)silanezirconium dichloride, which still contains impurities. Organometallics 1993, 12, 5012-5015 describes a multistage synthesis pathway to ethylenebis(2-indenyl)titanium dichloride. Due to the multistage synthesis and the numerous purification operations, the achievable yield is very low. Due to the synthesis pathway, the structural variety of ethylene-bridged ligands is limited.
EP-A-2-941 997 discloses ethylene-bridged bis(2-indenyl)zircono-cenes. These zirconocenes are used for the production of special low molecular weight polyolefins.
EP-A1-940 408 describes silyl-bridged 2-indenyl metallocenes and a process for the production of organometallic compounds with indenyl ligands attached in position 2.
Comparatively little is known about organometallic compounds with indenyl ligands fused in position 5,6 (for example tetrahydroindacenyl ligands). Example 3 of WO-98/09999-A1 discloses the production of a half-sandwich titanium complex with a tetrahydroindacenyl ligand. Availability of the tetrahydroindacenyl titanium complex bridged in position 1 is, however, unsatisfactory (overall yield  less than 1%). WO-98/49212-A1 and WO-98/27103-A1 describe the production of half-sandwich complexes with tetrahydroindacenyl ligands bridged in position 1 and substituted in position 2 and/or 3 and the use thereof as catalysts for polymerizing olefins.
Transition metal complexes with tetrahydroindacenyl ligands bridged in position 2 are not known.
It has now been found that such organometallic catalysts, the bridging of which begins in position 2 of at least one tetrahydroindacenyl anion, have particular characteristics as polymerization catalysts, in particular producing largely atactic polymers having elevated molecular weights in the (co)polymerization of xcex1-olefins. It was accordingly desirable to find a production process for such catalysts bridged in position 2 of at least one tetrahydroindacenyl anion.
Another object was to provide a catalyst which is suitable for synthesizing high molecular weight EPDM.
The present invention relates to a process for the production of transition metal organometallic compounds with 2-indenyl fused in position 5,6 as the first ligand of the formula 
in which
Q1, Q2 are identical or different and, as a substituent of the 2-indenyl system fused in position 5,6, mean hydrogen, C1-C4 alkyl, C6-C14 aryl, C7-C10aralkyl, C1-C4 alkoxy, C1-C4 alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
Q3 represents an optionally substituted alkylene residue which, together with the two carbon atoms of the indenyl residue, forms a ring system in position 5 and 6,
M1 is a transition metal from groups 4, 5 or 6 of the IUPAC 1985 periodic system of elements,
X means an anion,
n is a number from zero to four, which is determined by the valency and bond state of M1,
Y represents a bridge from the group of xe2x80x94C(R1R2)xe2x80x94, xe2x80x94Si(R1R2)xe2x80x94, xe2x80x94Ge(R1R2)xe2x80x94, xe2x80x94C(R1R2)xe2x80x94C(R3R4)xe2x80x94, xe2x80x94C(R1R2)xe2x80x94Si(R3R4)xe2x80x94 or xe2x80x94Si(R1R2)xe2x80x94Si(R3R4)xe2x80x94, in which R1, R2, R3 and R4 mutually independently mean hydrogen, halogen, linear or branched C1-C10 alkyl, C5-C8 cycloalkyl, C6-C14 aryl or C7-C10 aralkyl and
Z is a second ligand from the group of open-chain and cyclic, optionally anionic xcfx80-systems, xe2x80x94N(R5)xe2x80x94, P(R6)xe2x80x94, |N(R5R7), |P(R6R8)xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, |OR5xe2x80x94 or |SR5xe2x80x94, wherein the vertical line to the left of the element symbol N, P, O or S means an electron pair and the bond between Z and M1 is of an ionic, covalent or coordinative nature and in which R5, R6, R7 and R8 mutually independently have the range of meaning of R1 to R4 and R5 and R7 may additionally mean xe2x80x94Si(R1R2R3) and R6 and R8 may additionally mean xe2x80x94Si(R1R2R3), xe2x80x94OR1, xe2x80x94SR1 or xe2x80x94N(R1R2),
characterized in that a haloindene fused in position 5,6 of the formula 
in which Hal1 denotes Cl, Br or I and Q1, Q2 and Q3 have the above meaning, is reacted with an elemental metal selected from group 1, 2 or 12 of the IUPAC 1985 periodic system or a corresponding metal compound in a quantity in the range from 1 to 100 mol of elemental metal/metal compound per mol of (II) and with a dihalide of the bridge Y of the formula
Hal2-Y-Hal3xe2x80x83xe2x80x83(III), 
in which
Hal2 and Hal3 mutually independently mean Cl, Br or I and
Y has the above range of meaning, in a quantity of 1 to 20 mol of (III) per mol of (II), wherein in the event that Y has the meaning xe2x80x94Si(R1R2)xe2x80x94, xe2x80x94Ge(R1R2)xe2x80x94 or xe2x80x94Si(R1R2)xe2x80x94Si(R3R4)xe2x80x94, the reaction of (II) with (i) elemental metal/metal compound and (ii) with (III) may also proceed simultaneously, and the reaction product of the formula 
in which Q1, Q2, Q3, Y and Hal3 have the above meaning,
optionally after the isolation thereof, is reacted with a Z derivative of the formula
ZM2pxe2x80x83xe2x80x83(Va) 
or
ZR9pxe2x80x83xe2x80x83(Vb), 
in which
M2 denotes Li, Na, K or xe2x80x94MgHal4, in which Hal4 has the range of meaning of Hal2,
p represents the number one or two,
R9 represents hydrogen, xe2x80x94Si(R1R2R3) or Sn(R1R2R3) and
Z, R1, R2 and R3 have the above meaning,
with elimination of a compound of the formula
xe2x80x83M2Hal3xe2x80x83xe2x80x83(VIa)
or
R9Hal3xe2x80x83xe2x80x83(VIb) 
in which M2, R9 and Hal3 have the above meaning,
optionally in the presence of an auxiliary base to yield the 2-indenyl compound of the formula 
in which Q1, Q2, Q3, Y and Z have the above meaning, and which may be present as a dianion and in which Z may furthermore bear M2, R9 or an electron pair,
and is then further reacted with a transition metal compound of the formula
M1Xqxe2x80x83xe2x80x83(VIII), 
in which
M1 and X have the above meaning and
q is a number from two to six, which is determined by the oxidation state of M1.
The process is advantageously performed at temperatures in the range from xe2x88x92100 to 120xc2x0 C.
Metals of groups 1, 2 or 12 which may, in particular, be mentioned are lithium, potassium, sodium, magnesium, calcium, zinc, cadmium and mercury. The metals of groups 2 and 12 are preferred. It may also be advantageous to use the metals as a mixture with each other.
Corresponding metal compounds, which may be mentioned are butyllithium, magnesium-butadiene, magnesium-anthracene and corresponding compounds of the other stated metals.
It may be advantageous to separate the unreacted metals/metal compounds before the addition of (III).
As a rule, the corresponding metal halides metal Hal1Hal2 are formed on reaction with (III).
Moreover, as a rule, when (Va) or (Vb) are added, the corresponding compounds of the formulae
M2Hal3xe2x80x83xe2x80x83(VIa) 
or
R9Hal3xe2x80x83xe2x80x83(VIb) 
in which
M2, R9 and Hal3 have the stated meanings, are formed.
The invention furthermore relates to the transition metal organometallic compounds with 2-indenyl fused in position 5,6 as the first ligand of the formula which may be produced with the stated process 
in which
Q1, Q2 are identical or different and, as a substituent of the 2-indenyl system fused in position 5,6, mean hydrogen, C1-C4 alkyl, C6-C14 aryl, C7-C10 aralkyl, C1-C4 alkoxy, C1-C4 alkylthio, phenoxy, phenylthio, di-C1-C4-alkylamino, C6-C14-aryl-C1-C4-alkylamino, di-C6-C14-arylamino, dibenzylamino, tri-C1-C4-alkylsilyl, di-C1-C4-alkylboranyl, phenyl-C1-C4-alkylboranyl, diphenylboranyl, di-C1-C4-alkylphosphoryl, diphenylphosphoryl or phenyl-C1-C4-alkylphosphoryl,
Q3 represents an optionally substituted alkylene residue which, together with the two carbon atoms of the indenyl residue, forms a ring system in position 5 and 6,
M1 is a transition metal from groups 4, 5 or 6 of the IUPAC 1985 periodic system of elements,
X means an anion,
n is a number from zero to four, which is determined by the valency and bond state of M1,
Y represents a bridge from the group of xe2x80x94C(R1R2)xe2x80x94, xe2x80x94Si(R1R2)xe2x80x94, xe2x80x94Ge(R1R2)xe2x80x94, xe2x80x94C(R1R2)xe2x80x94C(R3R4)xe2x80x94, xe2x80x94C(R1R2)xe2x80x94Si(R3R4)xe2x80x94 or xe2x80x94Si(R1R2)xe2x80x94Si(R3R4)xe2x80x94, in which R1, R2, R3 and R4 mutually independently mean hydrogen, halogen, linear or branched C1-C10 alkyl, C5-C8 cycloalkyl, C6-C14 aryl or C7-C10 aralkyl and
Z is a second ligand from the group of open-chain and cyclic, optionally anionic xcfx80-systems, xe2x80x94N(R5)xe2x80x94, P(R6)xe2x80x94, |N(R5R7)xe2x80x94, |P(R6R8)xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, |OR5xe2x80x94 or |SR5xe2x80x94, wherein the horizontal line to the left of the element symbol N, P, O or S represents a covalent bond between Z and M1, wherein the vertical line to the left of the element symbol N, P, O or S means an electron pair and the bond between Z and M1 is of a coordinative not covalent nature and in which R5, R6, R7 and R8 mutually independently have the range of meaning of R1 to R4 and R5 and R7 may additionally mean xe2x80x94Si(R1R2R3) and R6 and R8 may additionally mean xe2x80x94Si(R1R2R3), xe2x80x94OR1, xe2x80x94SR1 or xe2x80x94N(R1R2).
Compounds of the formula 
in which Q1, Q2, Y, Z, X, M1 and n have the above meaning are preferred.
The process according to the invention is characterized by a sequence of reactions passing via the intermediate product of the above formula (IV). Such intermediate products have not hitherto been known. The present invention accordingly also relates to these intermediate products.
The invention furthermore relates to a process for the production of the intermediate products of the formula (IV) which is characterized in that a 2-haloindene fused in position 5,6 of the formula 
in which
Hal1, Q1, Q2 and Q3 have the above meaning,
is reacted with an elemental metal selected from group 1, 2 or 12 of the IUPAC 1985 periodic system or a corresponding metal compound in a quantity in the range from 1 to 100 mol of elemental metal/metal compound per mol of (II) and with a dihalide of Y of the formula
Hal2-Y-Hal3xe2x80x83xe2x80x83(III), 
in which
Y, Hal2 and Hal3 have the above meaning,
in a quantity of 1 to 20 mol of (III) per mol of (II), wherein in the event that Y has the meaning xe2x80x94Si(R1R2)xe2x80x94, xe2x80x94Ge(R1R2)xe2x80x94 or xe2x80x94Si(R1R2)xe2x80x94Si(R3R4)xe2x80x94, the reaction of (II) with (i) elemental metal/metal compound and (ii) with (III) may also proceed simultaneously.
Metals of groups 1, 2 or 12, which may, in particular, be mentioned are lithium, potassium, sodium, magnesium, calcium, zinc, cadmium and mercury. Metals of groups 2 and 12 are preferred. It may also be advantageous to use the metals as a mixture with each other.
Corresponding metal compounds which may be mentioned are butyllithium, magnesium-butadiene, magnesium-anthracene and corresponding compounds of the other stated metals.
It may be advantageous to separate the unreacted metals/metal compounds before the addition of (III).
As a rule, the corresponding metal halides metal Hal1Hal2 are formed on reaction with (III).
Moreover, as a rule, when (Va) or (Vb) are added, the corresponding compounds of the formulae
M2Hal3xe2x80x83xe2x80x83(VIa) 
or
R9Hal3xe2x80x83xe2x80x83(VIb) 
in which
M2, R9 and Hal3 have the known meanings, are formed.
The process is advantageously performed at temperatures in the range from xe2x88x92100xc2x0 C. to +120xc2x0 C.
The invention furthermore relates to a process for the production of the intermediate products of the formula (II), which is characterized in that the optionally substituted indanone of the formula 
is produced in the presence of a Lewis acid by reacting the aromatic compound of the formula 
with an acrylic acid derivative of the formula 
wherein
R10 means Cl, Br, I, a hydroxyl group or a C1-C10 alkoxy group,
wherein AlCl3, SbCl5, FeCl3, SnCl4, ZnCl2 or BF3 is preferably suitable as the Lewis acid,
and is then further reacted in accordance with the method described in J. Organomet. Chem. 568 (1998), 41-51 (example 3.10) to yield an indene fused in position 5,6 of the formula 
and is then further transformed into the dihalogen derivative (XIII) 
and hydrogen halide elimination is then performed. Methods for dihalogenation and subsequent hydrogen halide elimination are generally known to the person skilled in the art and are described, for example, in Patai, The Chemistry of Halides, Pseudo-Halides and Azides, pp. 1173-1227, New York, Wiley 1983.
Furthermore, the present invention relates to the use of the compounds of the formula (I) as catalysts both on a catalyst support (for example Al2O3, SiO2 and other inert supports) and without a support for the polymerization of monomers from the group of C2-C6 xcex1-olefins, C4-C6 diolefins and cyclo(di)olefins or for the copolymerization of two or more of the stated monomers, in particular for the production of amorphous, largely atactic polymers.
The present invention preferably relates to the described process and the compounds of the formula (I) producible therewith, in which Y has the meaning xe2x80x94Si(R1R2)xe2x80x94, xe2x80x94Ge(R1R2)xe2x80x94 or xe2x80x94Si(R1R2)xe2x80x94Si(R3R4)xe2x80x94, particularly preferably xe2x80x94Si(R1R2)xe2x80x94, and the reaction of (II) with (i) Mg or Zn and (ii) with (III) to yield the reaction product (IV) proceeds simultaneously.
Cyclic xcfx80-systems within the meaning of Z are, for example, substituted or unsubstituted cyclopentadiene, substituted or unsubstituted 1-indene, substituted or unsubstituted 2-indene, substituted or unsubstituted fluorene, which are attached covalently to the bridge Y and ionically, covalently or coordinatively to M1.
The present invention preferably relates to the process according to the present invention and to the transition metal organometallic compounds according to the present invention of the formula (I), in which, however, Z is replaced by the second ligand Zxe2x80x2, which has the meaning of substituted or unsubstituted cyclopentadiene, substituted or unsubstituted 1-indene, substituted or unsubstituted 2-indene, substituted or unsubstituted fluorene, xe2x80x94N(R5)xe2x80x94, xe2x80x94P(R6)xe2x80x94, |N(R5R7)xe2x80x94, |P(R6R8)xe2x80x94, xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, |OR5xe2x80x94 or |SR5xe2x80x94, in which R5 to R8 and the vertical lines have the above-stated meaning.
Further preferred second ligands are those of the formula Zxe2x80x3 with the range of meaning of xe2x80x94N(R5)xe2x80x94 or |N(R5R7)xe2x80x94, in particular in conjunction with Y=xe2x80x94Si(R1R2)xe2x80x94 and M1=Ti or Zr.
Compounds of the formula (I), in which Y=xe2x80x94Si(R1R2)xe2x80x94, M1=Ti or Zr and Z=xe2x80x94N(R5)xe2x80x94 are suitable in particular for the production of atactic polypropylene.
Linear or branched C1-C10 alkyl is, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert.-butyl, the isomeric pentyls, hexyls, octyls or decyls. C1-C4 alkyl is preferred, with methyl and ethyl being particularly preferred.
C5-C8 cycloalkyl is, for example, cyclopentyl, methylcyclopentyl, dimethylcyclopentyl, cyclohexyl, methylcyclohexyl, dimethylcyclohexyl, cycloheptyl, cyclooctyl, preferably cyclopentyl and cyclohexyl and the methyl and dimethyl derivatives thereof.
C6-C14 aryl is, for example, phenyl, naphthyl, biphenylyl, anthryl, phenanthryl, preferably phenyl.
C7-C10 aralkyl is, for example, benzyl, xcex1- or xcex2-phenylethyl, phenylpropyl or phenylbutyl.
C1-C4 alkoxy or C1-C4 alkylthio are, for example, methoxy, methylthio, ethoxy, ethylthio, propoxy, propylthio, isopropoxy, isopropylthio, butoxy, butylthio, isobutoxy and isobutylthio.
Aryl or the aromatic moieties of aralkyl may be identically or differently mono- or disubstituted by fluorine, chlorine, bromine, methyl, ethyl, methoxy or ethoxy.
Q3 is for example xe2x80x94(CR112)mxe2x80x94, where m=2, 3, 4, 5 or 6, wherein R11 has the range of meaning of R1 to R4, more preferably xe2x80x94(CH2)mxe2x80x94, where m=3, 4.
Halogen within R1 to R8 is, for example, fluorine, chlorine, bromine or various thereof, preferably chlorine.
M1 is for example Ti, Zr, Hf, V, Nb, Ta, Cr, W, Mo, preferably Ti, Zr, Hf, V, Nb, more preferably Ti, Zr, Hf, and most preferably Ti, Zr. M1 may be used both in the highest possible oxidation state and in a different, lower oxidation state and may occur in this form in the organometallic compounds. In many cases, it is advantageous initially to use M1 in a lower oxidation state and then to oxidize it to a higher valency with a mild oxidizing agent, for example PbCl2.
X is a singly or multiply charged anion from the group of fluoride, chloride, bromide, C1-C4 carboxylate, amide, C1-C4 alkyl, phenyl, benzyl, neopentyl and substituted or unsubstituted butadienyl, preferably chloride or fluoride; various of the stated anions may also be present.
Hal1, Hal2 and Hal3 within (II) and (III) are mutually independently Cl, Br or I, with Hal1 preferably being Br and Hal2 and Hal3 being Cl or Br.
The temperature for the reaction of (II) with Mg or Zn is in the range from xe2x88x9220xc2x0 C. to +120xc2x0 C., preferably from 0xc2x0 C. to +100xc2x0 C., more preferably +25xc2x0 C. to +80xc2x0 C.
The quantity of Mg or Zn is 1 to 100 mol per mol of (II). Quantities outside the stated range may, in principle, also be used. Below 1 mol of Mg or Zn per mol of (II), the reaction of (II) is incomplete and above 100 mol, no further advantage may be anticipated with regard to the completeness and rate of the reaction. Preferably, 1 to 10 mol of Mg or Zn, more preferably 1 to 5 mol of Mg or Zn, are used per mol of (II). Of the metals Mg and Zn, Mg is preferred for the reaction.
The temperature for the further reaction with (III) is likewise in the range from xe2x88x9220xc2x0 C. to +120xc2x0 C., preferably from 0xc2x0 C. to +100xc2x0 C., and most preferably from +25xc2x0 C. to +80xc2x0 C.
The quantity of (III) is 1 to 20 mol per mol of (II). The above statement with regard to the quantity of Mg or Zn applies to quantities outside this range. Preferably, 1 to 10 mol of (III), more preferably 1 to 2 mol of (III), are used per mol of (II).
Unreacted Mg or Zn and (III) are separated from the reaction batch in a manner known to the person skilled in the art and may be reused.
The process according to the present invention may be performed in the presence of a polar, aprotic solvent. Suitable solvents are for example, methylene chloride, chloroform, dimethylformamide, N-methylpyrrolidone and ethers. Of these, the ethers are preferred, for example, diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran and others known to the person skilled in the art. The quantity of solvent is selected such that (II) and the organomagnesium or organozinc compound arising therefrom are in dissolved form and the unreacted Mg or Zn may be separated, for example, by filtration or decanting or an analogous separation operation. This quantity is, for example, 50 to 1000% of the quantity of (II).
Y is preferably xe2x80x94C(R1R2)xe2x80x94, xe2x80x94Si(R1R2)xe2x80x94, particularly preferably xe2x80x94Si(R1R2)xe2x80x94.
In the event that Y has the meaning xe2x80x94Si(R1R2)xe2x80x94, xe2x80x94Ge(R1R2)xe2x80x94 or xe2x80x94Si(R1R2)xe2x80x94Si(R1RK)xe2x80x94, simultaneously reacting (II) with (i) Mg or Zn and (ii) with (III) is an elegant way of saving one reaction step.
In the event that the reaction of (IV) with (Va) or (Vb) to yield (VII) is performed in the presence of an auxiliary base, the following may be considered for this purpose: open-chain or cyclic tertiary aliphatic amines having a total of 3 to 30 C atoms, such as trimethylamine, triethylamine, tripropylamine, triisopropylamine, tributylamine, triisobutylamine, trihexylamine, trioctylamine, tridecylamine, N-methylpiperidine, N,Nxe2x80x2-dimethylpiperazine, diazabicyclononane (DBN), diazabicycloundecane (DBU), as well as amines with differing C chain lengths, such as N,N-dimethylbutylamine, N,N-dimethyloctylamine, N,N-dimethylstearylamine and the like, and aromatic amines, such as pyridine, methylpyridine, quinoline, N,N-dimethylaniline and the like.
The reaction mixture containing the organometallic compound (I) is worked up using operations known to the person skilled in the art, such as filtration, removal of volatile mixture constituents by distillation and crystallization.
The organometallic compounds of the formula (I) may be used as catalysts for (co)polymerizing C2-C12 xcex1-olefins, C4-C20 diolefins, cyclo(di)olefins or mixtures of two or more thereof. Monomers from the stated groups are, for example: ethylene, propylene, 1-butylene, 1-pentene, 1-hexene, 1-octene and the branched isomers thereof, isobutylene, 1,3-butadiene, 1,3- or 1,4-pentadiene, 1,3-, 1,4- or 1,5-hexadiene, 1,5-heptadiene, isoprene, chloroprene, norbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 4-vinyl-1-cyclohexene, dicyclopenta-diene, 7-methyl-1,6-octadiene and 5,7-dimethyl-1,6-octadiene.
The compounds of the formula (I) are frequently used for (co)polymerization in combination with co-catalysts.
Co-catalysts which may be considered are co-catalysts known in the field of metallocenes, such as polymeric or oligomeric alumoxanes, Lewis acids as well as aluminates and borates. In this connection, reference is in particular made to Macromol. Symp. vol. 97, July 1995, pp. 1-246 (for alumoxanes), and to EP-A1-277 003, EP-A1-277 004, Organometallics 1997, 16, 842-857 (for borates) and EP-A2-573 403 (for aluminates).
Suitable co-catalysts are, in particular, methylalumoxane, methylalumoxane modified by triisobutylaluminum (TIBA), as well as diisobutylalumoxane, trialkylaluminum compounds, such as trimethylaluminum, triethylaluminum, triisobutylaluminum, triisooctyl-aluminum, furthermore dialkylaluminum compounds such as diisobutylaluminum hydride, diethylaluminum chloride, substituted triarylboron compounds, such as tris(pentafluorophenyl)borane, as well as ionic compounds containing tetrakis(pentafluorophenyl)borate as the anion, such as triphenylmethyl tetrakis(pentafluorophenyl)borate, trimethyl-ammonium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, substituted triarylaluminum compounds, such as tris(pentafluorophenyl)aluminum, as well as ionic compounds containing tetrakis(pentafluorophenyl)aluminate as the anion, such as triphenylmethyl tetrakis(pentafluorophenyl)-aluminate, N,N-dimethyl-anilinium tetrakis(pentafluorophenyl)aluminate.
It is, of course, possible to use the co-catalysts as a mixture with each other. The most favorable mixing ratios should be determined by suitable preliminary testing. Such (co)polymerization reactions are performed in the gas, liquid or slurry phase. The temperature range for this purpose extends from xe2x88x9220xc2x0 C. to +200xc2x0 C., preferably from 0xc2x0 C. to 160xc2x0 C., more preferably from +20xc2x0 C. to +80xc2x0 C.; the pressure range extends from 1 to 50 bar, preferably from 3 to 30 bar. Additionally used solvents are, for example: saturated aliphatics or (halo)aromatics, such as pentane, hexane, heptane, cyclohexane, petroleum ether, kerosene, hydrogenated naphthas, benzene, toluene, xylene, ethylbenzene, chlorobenzene and the like. These reaction conditions for (co)polymerization are known in principle to the person skilled in the art.
Important polymers which may be produced with the organometallic compounds according to the present invention as catalysts, are those of ethylene and the copolymers thereof. Suitable comonomers are C2-C12 alkenes, such as ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene and arylalkenes, such as for example styrene. Further suitable comonomers are unconjugated dienes, such as 1,4-hexadiene, 1,5-heptadiene, 4-vinyl-1-cyclohexene, 7-methyl-1,6-octadiene and 5,7-dimethyl-1,6-octadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene and dicyclopentadiene. It is possible also to use mixtures of the stated comonomers.
The ethylene (co)polymers producible in this manner have molecular weights with Mw= greater than 100000 g/mol and molecular weight distributions with Mw/Mn= less than 4. The ethylene (co)polymers have intrinsic viscosities of greater than 1 dl/g, preferably of greater than 2 dl/g. Crystallinity values are less than 15%, wherein percentage crystallinity=(melt enthalpy/209 J/g)xc3x97100 and melt enthalpy is determined in J/g using the DSC method. Ethylene (co)polymers having melt enthalpies with a value of less than 5 J/g (DSC method) are more preferred. The ethylene (co)polymers are readily soluble in usual solvents such as hexane, heptane, diethyl ether or toluene.
It is in particular possible also to produce rubbers based on ethylene and one or more of the stated comonomers in the described manner. It is more preferred to copolymerize ethylene and propylene, wherein amorphous ethylene (co)polymers having an ethylene content in the polymer in the range from 30 to 70 wt. %, preferably from 40 to 65 wt. %, are obtained.
EPDM rubbers based on ethylene, propylene and a diene, preferably 5-ethylidene-2-norbornene, may also be produced in the described manner. The EPDM rubbers are distinguished in that they have elevated molecular weights and low crystalline contents.
High molecular weight atactic polymers, for example atactic polypropylene, may particularly effectively be produced using the organometallic compounds according to the present invention.
For example, the (co)polymerization of ethylene with or without the stated comonomers may be performed as follows: after conventional cleaning operations, a steel autoclave is charged with a solvent and a scavenger, for example triisobutylaluminum. The scavenger renders harmless any possible contaminants and catalyst poisons, for example water or other compounds containing oxygen. A compound of the formula (I) is then added as a catalyst precursor. The reactor is then charged with monomers up to a certain pressure, adjusted to a selected temperature and the polymerization initiated by adding one or more of the above-stated co-catalysts. Polymerization may proceed in a continuous or discontinuous process.